The Senate voted 52 to 46 on Feb. 17 to confirm President Donald Trump's nomination to head the Environmental Protection Agency, Scott Pruitt.
Pruitt has made a career of suing the EPA and has been attacked for his close ties to the fossil fuel industry, The New York Times reports.
Republican Sen. Susan Collins of Maine crossed party lines to vote against Pruitt, while Democrats Sen. Joe Manchin of West Virginia and Sen. Heidi Heitkamp of North Dakota, both states heavily dependent on the energy industry, backed Pruitt.
The Times revealed in an investigation that energy lobbyists used state stationary to draft letters for Pruitt to send to the EPA when he was Attorney General of Oklahoma. Major energy companies contributed to Pruitt's election campaigns.
Thousands of emails sent between Pruitt and energy companies are due to be released Feb. 21. Senate Democrats pushed for Pruitt's confirmation to be delayed until then, but their efforts failed.
"I reminded my colleagues that the release of these documents could be imminent and that we would be wise wait to vote on Mr. Pruitt’s nomination until we had the opportunity to review them -- and shame on us if we didn’t," Sen. Thomas Carper of Delaware told The New York Times.
President Trump has indicated his support for reducing the EPA's authority, as well as cutting the number of its employees.
"Mr. Pruitt has been nominated by a man who, as a nominee, as a president-elect and now as president, has made clear his goals to degrade and destroy the EPA," Carper added.
Republicans back Pruitt, who has expressed skepticism about human-caused climate change.
"Pruitt is just the candidate we need at the helm of the EPA," Republican Sen. Mitch McConnell, the majority leader, said. "He’s exceptionally qualified. He’s dedicated to environmental protection. And, as someone with state government experience, he understands the real-world consequences of EPA actions and knows that balance is the key to making policies that are sustainable over the long-term."
Pruitt previously questioned the suggestion that the EPA has the authority to regulate greenhouse gas emissions.
"If you go to the Clean Air Act today and go to Section 112 of the act ... if you go read the section in the Clean Air Act where it lists all of the hazardous air pollutants the EPA is authorized and empowered to regulate, guess what you won’t find," Pruitt said during a radio interview, according to Salon. "You won’t find carbon, you won’t find CO2."